Hi there , I have two FRDM-KW24D512 board . I have been trying to update their firmware because I can't download the program into them using IAR software (following the instruction :FRDM-KW24D512|Freedom Development Platform|Kinetis|NXP ) . So I did manage to get in the bootloader mode , which the green LED on the board kept blinking , however I can't find a appropriate OpenSDA debugger firmware for them , so I unplug the board and reconnect them .They are still in bootloader mode , the blue and red LED which will blink when the board plunged-in first time dose not blink , only the green LED .Then I try to download the Default firmware application bin file into them , them suddenly like dead , no respond at all , nothing in device manager and not even bootload drive .I tried to press and hold the reset button and plug the USB cable to the debug port to see if it still work , nothing happens .But if I plug in the other USB port , they do power on .How can I "un-brick" them ?